Late Devonian extinction

CambrianOrdovicianSilurianDevonianCarboniferousPermianTriassicJurassicCretaceousPaleogeneNeogene
Marine extinction intensity during Phanerozoic
%
Millions of years ago
CambrianOrdovicianSilurianDevonianCarboniferousPermianTriassicJurassicCretaceousPaleogeneNeogene
Comparison of the three episodes of extinction in the Late Devonian (Late D) to other mass extinction events in Earth's history. Plotted is the extinction intensity, calculated from marine genera.

The Late Devonian extinction consisted of several extinction events in the Late Devonian Epoch, which collectively represent one of the five largest mass extinction events in the history of life on Earth. The term primarily refers to a major extinction, the Kellwasser event, also known as the Frasnian-Famennian extinction,[1] which occurred around 372 million years ago, at the boundary between the Frasnian age and the Famennian age, the last age in the Devonian Period.[2][3][4] Overall, 19% of all families and 50% of all genera became extinct.[5] A second mass extinction called the Hangenberg event, also known as the end-Devonian extinction,[6] occurred 359 million years ago, bringing an end to the Famennian and Devonian, as the world transitioned into the Carboniferous Period.[7]

Although it is well established that there was a massive loss of biodiversity in the Late Devonian, the timespan of this event is uncertain, with estimates ranging from 500,000 to 25 million years, extending from the mid-Givetian to the end-Famennian.[8] Some consider the extinction to be as many as seven distinct events, spread over about 25 million years, with notable extinctions at the ends of the Givetian, Frasnian, and Famennian ages.[9]

By the Late Devonian, the land had been colonized by plants and insects. In the oceans, massive reefs were built by corals and stromatoporoids. Euramerica and Gondwana were beginning to converge into what would become Pangaea. The extinction seems to have only affected marine life. Hard-hit groups include brachiopods, trilobites, and reef-building organisms; the latter almost completely disappeared. The causes of these extinctions are unclear. Leading hypotheses include changes in sea level and ocean anoxia, possibly triggered by global cooling or oceanic volcanism. The impact of a comet or another extraterrestrial body has also been suggested,[10] such as the Siljan Ring event in Sweden. Some statistical analysis suggests that the decrease in diversity was caused more by a decrease in speciation than by an increase in extinctions.[11][12] This might have been caused by invasions of cosmopolitan species, rather than by any single event.[12] Placoderms were hit hard by the Kellwasser event and completely died out in the Hangenberg event, but most other jawed vertebrates were less strongly impacted. Agnathans (jawless fish) were in decline long before the end of the Frasnian and were nearly wiped out by the extinctions.[13]

The extinction event was accompanied by widespread oceanic anoxia; that is, a lack of oxygen, prohibiting decay and allowing the preservation of organic matter.[14][15] This, combined with the ability of porous reef rocks to hold oil, has led to Devonian rocks being an important source of oil, especially in Canada and the United States.[16][17][18]

  1. ^ Cite error: The named reference JenniferClack2007 was invoked but never defined (see the help page).
  2. ^ Becker, R. Thomas; House, Michael R. (13 March 1986). "Kellwasser Events and goniatite successions in the Devonian of the Montagne Noire with comments on possible causations". Courier Forschungsinstitut Senckenberg. 169: 45–77. Retrieved 19 April 2023.
  3. ^ Racki, 2005
  4. ^ McGhee, George R. Jr, 1996. The Late Devonian Mass Extinction: the Frasnian/Famennian Crisis (Columbia University Press) ISBN 0-231-07504-9
  5. ^ "John Baez, Extinction, April 8, 2006".
  6. ^ Sallan, L.; Galimberti, A. K. (2015-11-13). "Body-size reduction in vertebrates following the end-Devonian mass extinction". Science. 350 (6262): 812–815. Bibcode:2015Sci...350..812S. doi:10.1126/science.aac7373. PMID 26564854. S2CID 206640186.
  7. ^ Caplan, Mark L; Bustin, R.Mark (May 1999). "Devonian–Carboniferous Hangenberg mass extinction event, widespread organic-rich mudrock and anoxia: causes and consequences". Palaeogeography, Palaeoclimatology, Palaeoecology. 148 (4): 187–207. Bibcode:1999PPP...148..187C. doi:10.1016/S0031-0182(98)00218-1.
  8. ^ Stigall, Alycia (2011). "GSA Today - Speciation collapse and invasive species dynamics during the Late Devonian "Mass Extinction"". www.geosociety.org. Retrieved 2021-03-30.
  9. ^ Sole, R. V., and Newman, M., 2002. "Extinctions and Biodiversity in the Fossil Record - Volume Two, The earth system: biological and ecological dimensions of global environment change" pp. 297-391, Encyclopedia of Global Environmental Change John Wiley & Sons.
  10. ^ Sole, R. V., and Newman, M. Patterns of extinction and biodiversity in the fossil record Archived 2012-03-14 at the Wayback Machine
  11. ^ Bambach, R.K.; Knoll, A.H.; Wang, S.C. (December 2004). "Origination, extinction, and mass depletions of marine diversity". Paleobiology. 30 (4): 522–542. Bibcode:2004Pbio...30..522B. doi:10.1666/0094-8373(2004)030<0522:OEAMDO>2.0.CO;2. S2CID 17279135.
  12. ^ a b Stigall, 2011
  13. ^ Sallan, L. C.; Coates, M. I. (June 2010). "End-Devonian extinction and a bottleneck in the early evolution of modern jawed vertebrates". Proceedings of the National Academy of Sciences. 107 (22): 10131–10135. Bibcode:2010PNAS..10710131S. doi:10.1073/pnas.0914000107. PMC 2890420. PMID 20479258.
  14. ^ Girard, Catherine; Renaud, Sabrina (25 June 2007). "Quantitative conodont-based approaches for correlation of the Late Devonian Kellwasser anoxic events". Palaeogeography, Palaeoclimatology, Palaeoecology. 250 (1–4): 114–125. Bibcode:2007PPP...250..114G. doi:10.1016/j.palaeo.2007.03.007. Retrieved 15 January 2023.
  15. ^ Carmichael, Sarah K.; Waters, Johnny A.; Königshof, Peter; Suttner, Thomas J.; Kido, Erika (December 2019). "Paleogeography and paleoenvironments of the Late Devonian Kellwasser event: A review of its sedimentological and geochemical expression". Global and Planetary Change. 183: 102984. Bibcode:2019GPC...18302984C. doi:10.1016/j.gloplacha.2019.102984. S2CID 198415606. Retrieved 23 December 2022.
  16. ^ Wang, Pengwei; Chen, Zhuoheng; Jin, Zhijun; Jiang, Chunqing; Sun, Mingliang; Guo, Yingchun; Chen, Xiao; Jia, Zekai (February 2018). "Shale oil and gas resources in organic pores of the Devonian Duvernay Shale, Western Canada Sedimentary Basin based on petroleum system modeling". Journal of Natural Gas Science and Engineering. 50: 33–42. Bibcode:2018JNGSE..50...33W. doi:10.1016/j.jngse.2017.10.027. Retrieved 15 January 2023.
  17. ^ Dong, Tian; Harris, Nicholas B.; McMillan, Julia M.; Twemlow, Cory E.; Nassichuk, Brent R.; Bish, David L. (15 May 2019). "A model for porosity evolution in shale reservoirs: An example from the Upper Devonian Duvernay Formation, Western Canada Sedimentary Basin". AAPG Bulletin. 103 (5): 1017–1044. Bibcode:2019BAAPG.103.1017D. doi:10.1306/10261817272. S2CID 135341837. Retrieved 15 January 2023.
  18. ^ Smith, Mark G.; Bustin, R. Marc (1 July 2000). "Late Devonian and Early Mississippian Bakken and Exshaw Black Shale Source Rocks, Western Canada Sedimentary Basin: A Sequence Stratigraphic Interpretation". AAPG Bulletin. 84 (7): 940–960. doi:10.1306/A9673B76-1738-11D7-8645000102C1865D. Retrieved 15 January 2023.